Building a Portable DIY RV Water Filtration System

Ever been stressed about running out of water? Have you ever driven out of your way, leaving a pristine boondocking spot, just because your fresh water holding tank was low? Have you ever stayed in an overcrowded campground or RV park simply because they offered potable water? I have, and I was determined to come up with a solution to this vexing problem once and for all. I thought to myself, if EarthRoamer can do it, so can I—and I did. I created a five-stage water filtration system that runs off the sun’s energy and produces drinking-quality water from any natural water source. If you’re interested in building your own DIY system, read on to find out what I did to maybe avoid some of the same mistakes along the way.

While boondocking in a truck camper, I found that water is the biggest limiting factor on how long I can stay away from civilization. One of the features of my Northstar Igloo that sold me was the large, 40 gallon fresh water tank. I also liked the fact that the cassette toilet tank is independent of the fresh water holding tank. I love to camp, but I have always been a clean freak. I love my showers. Showers, however, will blast through your water supply even if you take a Navy shower. I admit it, I’m a water hog.

“Water, water, everywhere, and all the boards did shrink;

Water, water, everywhere, nor any drop to drink.”

The Rhyme of the Ancient Mariner, 1834

I spent many hours, driving around, looking for potable water. I frequented fire stations, campgrounds, and even bartered with homeowners, trading candy for iron-laden well water. I carry a water bandit and even a municipal T-wrench used to access water spigots with no handle. All the while, I was surrounded by rivers, reservoirs, and streams. There had to be a solution to get at this water. After all, on a smaller scale I filtered water on bikepacking trips from natural sources and showered from them with a compact shower.

I started to envision a water filtration system that could pump water from any river, lake or stream into my camper’s fresh water holding tank. I have a background in biology, so I knew what needed to be filtered out. I also have a knowledge of electrical systems and plumbing, but did not know what products were available as far as pumps and water filters go. I also knew I had to decide between either an AC pump or a DC pump. I was also aware of UV filters, but unsure if they were a good choice. There is actually a video and materials list on the RV Water Filter Store website, but the website didn’t “filter out” their products to the level I wanted. The company’s website was helpful to a point, but I needed more help.

I emailed the RV Water Filter Store and was immediately and enthusiastically answered by David Brannam.  Instead of casting negativity on my project, David loved the experimental aspect of it, which has become a collaboration between him and I. According to him, no one had attempted to do exactly what I was trying to accomplish. David is extremely knowledgeable, helpful and loves challenges. I will outline what we came up with in the end and then describe the pitfalls associated with the project for those who are interested. All part numbers listed in this article correlate to RV Water Filter Store item numbers.

My Water Filtration System

The filtration portion of the project consists triple canisters (#B2301), which are slimmer than the “big blue” house filters. In order form the pump end to the outlet, I needed a 1 micron washable sediment filter (#A1105), a Virus Hero 0.2 micron filter (#A1405), and a KDF/GAC granulated carbon filter (#A1206). The sediment filter removes dirt, silt and larger particles in the water, saving my more expensive bacteria/virus and carbon filters and extending their life. It is washable and reusable. The Virus Hero filter removes bacteria such as Giardia and even viruses. This filter can be replaced by using a chemical called Purogene widely used in the airline and boating industry. This would create an increased flow rate. I did buy some, but I wanted to go chemical-free. Finally, the granulated carbon filter removes harmful chemicals, improves taste, and is resistant to clogging unlike carbon block filters. Also required are an RV hose and a shorter pickup hose with a screen prefilter on one end. These hoses can be purchased anywhere.

Which order should the three filters be in from the water source? You can do the washable prefilter then the carbon granulated then the virus, or the prefilter, the virus, then the carbon. I do it the latter way, so if any carbon comes out it does not block the virus filter.

The pumping and power part of the system comes from a high pressure RV pump from Aquajet (#D1002), a custom harness made from an extension cord female end with polarity marked, an on/off switch, some fuses, fused battery clamps (similar to jumper cables) with the male end of an extension cord (with polarity marked) and a quality extension cord. In this way, I can adjust the reach to the water by simply utilizing longer hoses and extension cords, but as a general rule I try to keep the length to less than 50 feet.

The filters sit near the water source with the short 6-foot pickup hose in the water. The filter housing has a screen on one end and the pump has a Shurflo prescreen as well. The pump sits between the pickup hose and the filter housing. The outlet of the filter housing connects to a RV hose which goes into my water fill port on my camper. I usually attach a float on the pickup hose to keep it off the bottom or tie it to a long stick, so I can control it’s placement. I have solar, so in effect I am using the sun to pump clean water into my tank at a rate of about one gallon per minute. The whole system breaks down and fits in a plastic tote that resides behind the driver’s seat. Read on if you would like to know about the problems I encountered and why I made some of the decisions I made.

I was pretty adamant against using chemicals in my system despite David’s assurance that the chemical Purogene is safe. That led me to try a ceramic filter. David cautioned that the flow rate of these filters was extremely low. Possibly .5 gallon per minute or less. He also steered me away from UV filters due to their fragility in an off-road environment. UV filters are also dependent on power and a correct flow rate to function properly. DC UV filters are extremely expensive.

First, I chose the same pump as I had in my camper for redundancy. If my camper’s water pump died, I could simply swap pumps and be good to go, right? Nope! The resistance of the ceramic filter paired with the low pressure of the pump made the system unusable. To solve this problem, David recommended the Aquajet pump, which is American made, and has a much higher working pressure.

Next, the ceramic filter developed a crack, and when I was inspecting it, it crumbled. Needless to say I would not recommend an expensive ceramic filter either. The Virus Hero technology did not exist at that time, so I am happy that there is now a solution. The Virus Hero filter is a 0.2 micron filter with a high flow rate compared to ceramic, is lighter, and less prone to damage by far. In comparison, a Giardia cyst is about 1 micron in size.

Lastly, I went back and forth on the power part of the system. I could have used my generator and an extension cord paired with an AC pump, but I could not find a portable AC pump that was certified for drinking water. I also envisioned times when I wouldn’t want to bother others with generator noise. It’s also cool to use the sun and my camper’s 12 volt batteries to power my system. I know there will be critics condemning my use of AC extension cord in my harness, and even using an extension cord to deliver DC power, but it is fused at every connection. Nothing has gotten warm and it works. Wire is wire, right?

Final Thoughts

Building this DIY water filtration system was a lot of fun. I love being able to be camped by a river, lake or stream and not run out of water. The water from my system is pure and safe to drink, nor am I limited by the water in my tank. Yes, there were some failures along the way, and it was not an inexpensive project—about $525 for everything—but I learned a lot, used problem solving skills to come up with a solution, and ended up with a very useful system for my camper. I can’t thank David Brannam or the RV Water Filter Store enough for this collaboration and his enthusiasm towards the project encouraging me to keep going. There are very expensive systems on the market similar to mine, but I’m proud of the fact that I built it myself and ironed out the kinks for a lot less money. Happy camping!

Note: All components of the system were purchased by the author with the exception of the Virus Hero filter which was provided for evaluation in the system.